Conventionally, in radar apparatuses, underwater detection devices, etc., signal processing devices which perform a detection around the device by transmitting a transmission signal, receiving a reception signal, and analyzing the reception signal are known. This kind of signal processing device may perform pulse compression on the reception signal to improve an S/N ratio. JP2012-220449A discloses this kind of signal processing device.
The signal processing device of JP2012-220449A performs pulse compression on a reception signal received from a radar antenna to generate a pulse compressed signal. The signal processing device also calculates a moving average value of an envelope of the reception signal to generate a pseudo signal of side lobes of the pulse compressed signal. The signal processing device removes the pseudo signal of the side lobes from the pulse compressed signal. Thus, side lobes included in the pulse compressed signal can be removed.
However, in the processing described in JP2012-220449A, by removing the pseudo signal of the side lobes calculated as described above from the pulse compressed signal, the signal level of a main lobe of the pulse compressed signal lowers and the S/N ratio drops.